Is there a sutta at all where the Buddha urges someone not to believe him just because he has said it? (accept the kalama sutta)

I can't think of one. In fact the only one that comes to mind says almost exactly the opposite of this.

Bhikkhus, for a faithful disciple who is intent on fathoming the Teacher’s dispensation, it is fitting that he conduct himself thus: “The Blessed One is the Teacher; I am his disciple. The Blessed One knows; I do not know.”(Kīṭāgiri Sutta, MN. 70)

The Buddha said that those who simply believe others are not truly wise. A wise person practices until he is one with the Dhamma, until he can have confidence in himself, independent of others.

On one occasion, while Venerable Sāriputta was sitting, listening respectfully at his feet as the Buddha expounded the Dhamma, the Buddha turned to him and asked,

''Sāriputta, do you believe this teaching?''

Venerable Sāriputta replied, ''No, I don't yet believe it.''

Now this is a good illustration. Venerable Sāriputta listened, and he took note. When he said he didn't yet believe he wasn't being careless, he was speaking the truth. He simply took note of that teaching, because he had not yet developed his own understanding of it, so he told the Buddha that he didn't yet believe - because he really didn't believe. These words almost sound as if Venerable Sāriputta was being rude, but actually he wasn't. He spoke the truth, and the Buddha praised him for it.

''Good, good, Sāriputta. A wise person doesn't readily believe, he should consider first before believing.''

The Buddha once asked Sariputta, "Do you believe what I have been explaining to you?" Sariputta answered, "Yes, I see that it is so." The Buddha asked him, "Are you saying this just out of faith in me?" Sariputta answered, "No, I answered in agreement not because of faith in the Blessed One, but because I clearly see for myself that it is so." [Pubbakotthaka Sutta, Saim. S.V. 220]